Field
The present invention relates to a method of controlling a fuel cell system.
Related Art
In a fuel cell system, a fuel gas, for example, hydrogen gas is consumed with operation of a fuel cell for power generation, so that there is a need to fill the hydrogen gas into a tank. A proposed configuration for the fuel cell system transmits data with regard to gas filling to and from a gas supply side by communication in the process of filling the hydrogen gas. For example, a system described in JP 2011-156896A sends temperature data in a tank to the gas supply side by communication. The gas supply side controls the filling rate of hydrogen based on the received data and fills hydrogen at the controlled filling rate.
This proposed control technique allows data to be transmitted between the fuel cell system mounted on a vehicle and the gas supply side by communication and advantageously ensures safe supply of hydrogen. The vehicle equipped with the fuel cell and the tank may, however, require a control for the purpose of maintaining the function of the fuel cell even when the vehicle is at stop (vehicle speed=0). In the state that the vehicle is at stop, filling of hydrogen as the fuel is enabled, so that the required control may be performed simultaneously with gas filling. The control of the fuel cell in this state, however, has not, been sufficiently considered. For example, a main stop valve of the tank may be opened to allow for supply of the gas, with a view to preventing water from being frozen in the fuel cell during an operation stop period of the fuel cell. Regulation of the relationship between such control and gas filling has not been considered.
A lid for gas filling may be kept open due to some cause, such as carelessness or a wrong valve closing operation of a gas filling operator. In this case, since the lid is open, the gas filling operator can fill the gas. There has, however, been no consideration about permission or prohibition of gas filling according to the operating condition of the fuel cell. The inventors have found the necessity to regulate the relationship between control of the fuel cell and gas filling during the operation stop period of the fuel cell and completed the invention.